Nishihara Kazuhide, Yoshimine Shin-Ichiro, Goto Takahiro, Ishihata Kiyohide, Kume Ken-Ichi, Yoshimura Takuya, Nakamura Norifumi, Arasaki Akira
Associate Professor, Department of Oral and Maxillofacial Functional Rehabilitation, Graduate School of Medicine, University of the Ryukyu, Okinawa, Japan.
Associate Professor, Department of Oral and Maxillofacial Surgery, Field of Oral and Maxillofacial Rehabilitation, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan.
Oral Surg Oral Med Oral Pathol Oral Radiol. 2017 May;123(5):606-612. doi: 10.1016/j.oooo.2017.01.007. Epub 2017 Jan 24.
The purpose of the present study was to elucidate the anatomic characteristics of the maxillary premolars for the planning of dental treatment using cone beam computed tomography (CBCT).
CBCT images were obtained for 150 maxillary premolars in 68 patients. The internal angle formed by the long axis of the maxillary premolars and the long axis of the alveolar bone was evaluated on the cross-sectional images. The vertical relationships between the maxillary premolars and the maxillary sinus were classified into 5 categories. The bone width and internal angle were compared among the images classified into the 5 categories.
The internal angle was 25.5 ± 6.9° at the maxillary first premolars. The incidence of Type I in the maxillary first premolars was 46.7%. In the maxillary second premolars, the incidence of Type I (14.7%) was significantly lower than the total incidence of Types II, III, IV, and V (85.3%). Type I had the significantly largest internal angle (28.0 ± 7.7°) among all types for the maxillary first premolars.
When considering dental treatment in the maxillary premolars, one should observe the inclination of the maxillary premolars to the alveolar bone as well as the position of the inferior wall of the maxillary sinus.
本研究旨在利用锥形束计算机断层扫描（CBCT）阐明上颌前磨牙的解剖特征，以用于牙科治疗计划。
获取了68例患者150颗上颌前磨牙的CBCT图像。在横断面图像上评估上颌前磨牙长轴与牙槽骨长轴形成的内角。将上颌前磨牙与上颌窦的垂直关系分为5类。比较了分为5类的图像之间的骨宽度和内角。
上颌第一前磨牙的内角为25.5±6.9°。上颌第一前磨牙I型的发生率为46.7%。在上颌第二前磨牙中，I型的发生率（14.7%）显著低于II、III、IV和V型的总发生率（85.3%）。对于上颌第一前磨牙，I型在所有类型中具有显著最大的内角（28.0±7.7°）。
在考虑上颌前磨牙的牙科治疗时，应观察上颌前磨牙相对于牙槽骨的倾斜度以及上颌窦下壁的位置。
